Lesson: The enzyme catalase splits hydrogen peroxide into water and oxygen.
What Happened: Adding yeast to hydrogen peroxide caused it to foam up with oxygen bubbles, which re-ignited an extinguished splint.
Science educator Robert Krampf has a collection of home science videos -- many but not all about chemistry -- on his website. He recently re-instated his email list, and I decided to try today's Experiment of the Day with some friends who are visiting. You can see Krampf explaining the experiment as he performs it on his website, which I have added to the sidebar. Here is an excerpt:
You will need:We did not get the dramatic results that he gets in the video, but after a few tries we figured out that you need to let the skewer burn for few minutes to get hot enough to reignite.
- a wooden, cooking skewer
- a lighter
- 3% hydrogen peroxide (from the grocery or pharmacy)
- a cup or glass
Pour some hydrogen peroxide into the glass. Sprinkle some of the yeast into the peroxide and give it a stir. Very quickly you will see bubbles rising, producing foam on top of the liquid.
Here is an explanation of how our bodies use catalase in the same way:
Hydrogen peroxide is a toxic by-product of respiration. Organisms that
obtain energy by oxidation of foods must develop mechanisms to limit the
damage it causes. This is primarily accomplished by a class of enzymes
called catalases, which catalyze the reaction2 HOOH --> 2 H2O + O2